From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE7FDC43603 for ; Wed, 11 Dec 2019 17:12:57 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 720842054F for ; Wed, 11 Dec 2019 17:12:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="HcsFv2I+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 720842054F Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0C2E06B3304; Wed, 11 Dec 2019 12:12:57 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 073786B3305; Wed, 11 Dec 2019 12:12:57 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id EA4AC6B3306; Wed, 11 Dec 2019 12:12:56 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id D1F2F6B3304 for ; Wed, 11 Dec 2019 12:12:56 -0500 (EST) Received: from smtpin30.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 8D1F62C14 for ; Wed, 11 Dec 2019 17:12:56 +0000 (UTC) X-FDA: 76253505552.30.note20_36b82883baa4b X-HE-Tag: note20_36b82883baa4b X-Filterd-Recvd-Size: 4493 Received: from mail-wr1-f68.google.com (mail-wr1-f68.google.com [209.85.221.68]) by imf03.hostedemail.com (Postfix) with ESMTP for ; Wed, 11 Dec 2019 17:12:55 +0000 (UTC) Received: by mail-wr1-f68.google.com with SMTP id g17so24905492wro.2 for ; Wed, 11 Dec 2019 09:12:55 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=87+nbO7EsRQpe1wmSikO8vry0s4iwAAY074PAWZUn2w=; b=HcsFv2I+5GpN8tthV67smYXfufVMlWaYkFgMpkaFzDGdfjp3TGIZLjlMspfT4yePt8 dFSnPi7iQLJduP3wwTLzsCAM9YhX++2smHKxYvO/dNtL0r/Cfx0wTLsJASTpLU33FaFd vV2cmdcUjYag4Yspdav4q6tvir6wnV5/6ZWzOCYOIEzS2dVUKOv+w6eTtgQxfZSIyIeI tY8Q3yuYWrKD7iczRVzQMwyU0sz8+NBZyQZj5hcREfBBKevQUlvjvfh2mRKNXC9eaaid HtqBvKiHPHM4TD/9eJI85G//q4Q5ANEs2JUVrHz+jwzjo7KLz3C4KxqzjOSCx9RpkIFM jWWw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=87+nbO7EsRQpe1wmSikO8vry0s4iwAAY074PAWZUn2w=; b=kTQ7A/w4YROsKGa6sUsRxvArOjBXaNHTIXbJsDy5KzmoYSz3UsdgCAcwzpb0YOrH4o LdKLHp/tZH6p8gXzDrwJzB4n+C41j5mWAd04bL91QZl6LoXNgwhA4Ig1eWmSiBZ/dp30 Nm0/mKX1USjdCmHtKEBnBQHC5aHHUj0lvxMiL6uAc4x/w8pariEAca9CYKa3a91Lad71 8lKWgmwIALwVq37yPWZupLphi7ZfWHnDph0YEEzpX/2PvXUU7u+MpKR1QQAOEZVS0xqh 8BtK/MX2yX/33QzVpq9FKyoDyFM7riPkjoVWH4NuAjprjGV0gUj+jjNMJiMjk3fAb2Io WIeA== X-Gm-Message-State: APjAAAWJeR7nqbaUJlEXy3mEtIbcbvvc9nAqEjquBWxXEMdJO/BIkqws 8KtEKpMm/chMiEbqZIf24VA= X-Google-Smtp-Source: APXvYqweJn+YpFwyn3LDIvxX4iMjbKa0WcfWqrhUUtEz4LpLSFHJwQKsC27YRGAVas14wLiu98uruA== X-Received: by 2002:adf:df03:: with SMTP id y3mr996018wrl.260.1576084374686; Wed, 11 Dec 2019 09:12:54 -0800 (PST) Received: from ltop.local ([2a02:a03f:40f6:4600:d98a:4956:14c2:2b5d]) by smtp.gmail.com with ESMTPSA id 2sm2973189wrq.31.2019.12.11.09.12.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 11 Dec 2019 09:12:53 -0800 (PST) Date: Wed, 11 Dec 2019 18:12:52 +0100 From: Luc Van Oostenryck To: Steven Price Cc: kbuild test robot , Mark Rutland , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-mm@kvack.org, "H. Peter Anvin" , Will Deacon , "Liang, Kan" , x86@kernel.org, Ingo Molnar , Arnd Bergmann , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Borislav Petkov , Andy Lutomirski , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, kbuild-all@lists.01.org, Ard Biesheuvel , linux-kernel@vger.kernel.org, James Morse , Andrew Morton Subject: Re: [PATCH v16 13/25] mm: pagewalk: Don't lock PTEs for walk_page_range_novma() Message-ID: <20191211171252.fdbdqn2nrze637gm@ltop.local> References: <20191206135316.47703-14-steven.price@arm.com> <201912101842.KIXI4yCg%lkp@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Wed, Dec 11, 2019 at 03:54:06PM +0000, Steven Price wrote: > On 10/12/2019 11:23, kbuild test robot wrote: > >>> include/linux/spinlock.h:378:9: sparse: sparse: context imbalance in 'walk_pte_range' - unexpected unlock > > I believe this is a false positive (although the trace here is useless). > This patch adds a conditional lock/unlock: > > pte = walk->no_vma ? pte_offset_map(pmd, addr) : > pte_offset_map_lock(walk->mm, pmd, addr, &ptl); > ... > if (!walk->no_vma) > spin_unlock(ptl); > pte_unmap(pte); > > I'm not sure how to match sparse happy about that. Is the only option to > have two versions of the walk_pte_range() function? One which takes the > lock and one which doesn't. Yes. -- Luc